Darwin (was: Phylogenetic evidence)

[SKÁLA Zdenek]

-----Original Message-----
From: Richard Jensen
If I take this literally, then you are arguing that there can exist a clade in which the objects have absolutely nothing in common ("...members do not share any character state in common...").  If that's the case, then the "clade" does not exist - it cannot be supported by any evidence and, in my mind, consists of two mutually exclusive classes of unknown affinity.

Can you provide an example of such a clade?
===========
Um, am I wrong here? What about the character matrix (+ = apomorphy)
   1 2 3 4 5 6 7 8
A  - + + + + + + +
B  + - + + + + + +
C  + + - + - - + +
D  + + + - - - - -

... does not it result in a cladogram (((AB)C)D) ? If yes (and perhaps I am missing something here), then we have a clade ABCD where the species do not share any single common character state.
Best!
Zdenek